Antibiotic resistance development and human health risks during wastewater reuse and biosolids application in agriculture

The reuse of treated wastewater (TWW) and sewage sludge are considered as solutions to the limited water resource and sludge disposal issues, respectively. The associated environmental and human health risks need to be analyzed to assess whether they are safe solutions or not. This paper discusses issues that relate to the accumulation of antibiotics and antibiotic resistance (AR) determinants in agricultural lands and crops, following TWW irrigation and biosolid amendment. Exposure assessment and dose-response assessment are the two important aspects of risk assessment discussed in this paper. Finally, research gaps in current knowledge that are relevant to a comprehensive and quantitative AR risk assessment were identified which includes: 1.) Studies on soil conditions that increase the frequency of horizontal gene transfer (HGT) between native soil resistome and pathogenic microbes in biosolids and TWW 2.) Holistic studies that examine the accumulation or dissipation of antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) from the irrigation/biosolids application stage to crop consumption stage 3.) The influences of soil environmental conditions (e.g. salinity, nutrients) on the fate of ARB and ARGs in soil and translocation in edible plants 4.) The development of dose-response models that explicitly incorporate the potential for ARGs transfer between microbes when quantifying the risks of infection due to ARB. (C) 2020 Published by Elsevier Ltd.

Automated summary

This paper discusses the impacts of treated wastewater and sewage sludge reuse on the accumulation of antibiotics and antibiotic resistance genes in agricultural lands and crops, emphasizing the importance of exposure assessment and dose-response assessment in risk assessment. The study also identifies research gaps in current knowledge, highlighting the need for further investigation into soil conditions affecting gene transfer, environmental factors affecting the migration of antibiotic resistance genes in soil and crops.